It is known for a vehicle assembly to include a lock arranged to maintain a first part of the assembly in a particular position with respect to a second part of the assembly.
An example of such a vehicle assembly is an aircraft landing gear assembly, which may include a down lock and a ground lock.
The purpose of a down lock is to lock a landing gear assembly in a deployed condition. An actuator may be provided to unlock the down lock, thereby enabling the landing gear assembly to move to a stowed condition. Accidental actuation of the down lock actuator when the aircraft is on the ground can result in the aircraft fuselage striking the ground.
As such, it is common to provide a ground lock to inhibit unlocking of the down lock while the ground lock is in a locked condition. A ground lock is generally a simple mechanical lock. In one example, the arms of a lock link are each provided with a hole, the holes being located so as to become coaxially aligned when the landing gear is in a deployed condition. A pin is manually inserted into the holes to inhibit articulation of the lock link, thereby inhibiting retraction of the landing gear. Prior to take off, a user may remove the pin such that the landing gear can be stowed following takeoff.
Ground lock accessibility is therefore a consideration at the design stage of a landing gear assembly. The present inventor has identified that this can result in a landing gear assembly receiving a sub optimal geometry.
Known vehicle assembly locks can also be adversely affected by movement of the vehicle assembly in use. To address this problem, it is known to provide a substantial biasing device, such as a spring, to maintain the lock in a particular condition while the vehicle assembly is moving.
However, the present inventor has identified that the size and/or mass of such biasing devices can be reduced, and in some cases eliminated.